Facility with wells having multiple horizontal galleries for lowering water tables

ABSTRACT

A facility with wells for lowering water tables has a set of enlarged horizontal gallery borings, which descend to a first impermeable layer, and extend therein at a length many times greater than the distance below ground level. Each boring has collecting piping having multiple borings, and at least one water extracting pipe associated with a corresponding extracting pump which drives water outside towards surface draining streambeds.

FIELD OF THE INVENTION

This patent of the invention has as main object A FACILITY WITH WELLS HAVING MULTIPLE HORIZONTAL GALLERIES FOR LOWERING WATER TABLES, which main advantage is to cover a large operating range with very little costs of facility and maintenance, thus contributing with the possibility of effectively fighting against the problem of progressive rise of water tables in urban populations.

More precisely, this invention provides for novel pumping facility for extracting underground water with the aim of causing lowering, to appropriate levels, of water tables. It is intended to lower underground sheets of water and keep them at the ideal depth based on the hydrogeological features of each region.

The invention comprises a clearly novel pumping facility since it resorts to the use of a plurality of horizontal gallery wells with great length, each of which has an own pumping resource, constituting a hydric collecting facility having an extremely functional and efficient incorporated draining, mainly because a plurality of wells having these features can cover a great operating range.

With this facility, it is possible and economically feasible, to lower water table in those areas where, due to different reasons, it is dangerously close to the ground surface, blocking its absorbing capacity and therefore hampering natural raining water uptake as well as the normal operation of static sewer system (cesspit, nitrifying beds, etc.).

The inventive facility is also very appropriate for uptaking water for human consumption and irrigation, and also for remedying contaminated subsoil, as it usually occurs in regions where oil refineries, chemical plants, etc., are installed.

PRIOR ART GENERAL FEATURES

As it is known, climatic change and rise of seas is a fact, hence, there are numerous urban regions where the progressive rise of water tables is evident.

In many cases, this process of water table rise has reached a critical level where the level of underground sheets of water raised to the degree of flooding basements and gardens.

The problem becomes worse in those localities where there is no sewer network laying, thus flooding septic wells, mixing sheets of water and making their contents flow.

Skilled people state that this progressive rise is a consequence of the fact that companies in charge of obtaining and distributing running water have stopped extracting subsoil water. They prefer to extract water from the river and to make it drinkable since it would be easier to obtain a better quality liquid.

When stopping extracting subsoil water, the phreatic level is raised, and this is occurring due to the fact that not only companies in charge of water exploitation, have stopped extracting subsoil water, but also various factories which extracted water for their industrial activities have been closed.

On the other hand, currently existing factories are being asked to connect to network and stop pumping water since, the usufruct of subsoil liquid is owned by companies which have entered an agreement for its exploitation with the State.

In this respect, it is cited the report written by Mr. Fernando DIAZ, holding Bachelor Degree in Geology, hydrogeologist and Judicial Expert, published in the newspaper “La Nación” of Argentina on Jul. 28, 2000.

This expert performed an study about the environmental impact to an specific city of the province of Buenos Aires, Argentina, stating that hygiene conditions in which the affected population lives, are the worst ones, not only because of the diseases that contaminated water transmits, but also because of the humidity that is generated and which causes uninhabitability conditions in homes.

The expert states that there are various concurrent elements which have been increased producing this phenomenon. Among them, not extracting subsoil water, lack of sewer, rains and the reduction of absorbing surfaces are highlighted.

He states that the only solution is to continue extracting water from the aquifer (deeper subsoil river of each area).

This phenomenon also occurs, mainly due to the disproportion that exists between the great extension of areas which already have network water, and, at the same time, the poor development of the sewer network. That is to say, an important quantity of liquid is discharged to the underground sheet of water which should be returned to the river.

The companies in charge of the running water exploitation have a different opinion, which state that, in fact, the problem is due to climatic changes since at present more rains than before are registered, and also due to the doubtless reduction of absorbing surfaces, because of paving and building constructions in areas that were free before.

The problem is worsened also due to the demographical growth, noting numerous cases of population settlements in floodable or flooded areas, where water tables are naturally located at historically high levels.

For these reasons, experts advise that the best way of ensuring lowering of water tables consists of pumping water directly from underground rivers again, as it is the only way to ensure uniform lowering involving wide regions.

Likewise, they state that subsoil water is always better than drinkable water. They also suggest that if in any case low quality is detected, it should be pumped, allowed to run towards streams because the condition of those carrying industrial wastes or which are open sky sewers, is further improved.

After setting forth the existing problem, a solution which is being spread mainly in diverse urban areas, consists of performing direct pumping for extracting water trying to achieve the mentioned water table lowering.

However, this solution is not totally efficient because local or much focalized results are only obtained; they are only useful for one house.

In fact, for fighting against this scourge, government entities have installed very large quantities of lowering pumps in those districts which are more affected.

However, this solution is not the best one as it has to be progressive, and additionally, the liquid has to be withdrawn without drawing sediments because buildings could be affected.

On the other hand, the presence of a great quantity of lowering pumps doubtlessly demands troublesome maintenance tasks making the service more expensive.

In order to solve this problem which was set forth, a research has been disclosed which gave rise to the Patent of the Invention in Argentina AR 029505 dated Sep. 28, 2007 belonging to the same title holder of this invention.

In such research it is proposes that a lower quantity of lowering pumps be used covering a larger operation range with less work of maintenance.

It is about a facility suitable for being located as system for lowering water tables in a determined geographic location, which comprises, in combination, a vertical boring extending, rectilinearly up to the first impermeable layer (phreatic aquifer), which lower end is communicated with a collecting subsoil enclosure, arranged in communication with the aquifer and below such vertical boring, which is in communication with a plurality of enlarged horizontal gallery borings extending across the aquifer, from a source point and to an end point, located on the surface and separated from each other at a length many times greater than the height of the vertical boring.

Its operating conception is based on collecting liquid from the water table directing it towards a subsoil enclosure.

Such water collecting task is performed by gravity avoiding from the beginning sediment drawing.

The mentioned collecting subsoil enclosure is located in communication with the first impermeable stratum or phreatic aquifer or Pampean aquifer. That is to say, by means of a previous study the optimum depth towards which the water table should be lowered is determined and it is the place where the enclosure is located, such that it is always based on the hydrogeological features of each area.

At the same time, the referred enclosure is communicated with a vertical boring extending up to the surface such that, by pumping, accumulated water shall be able to be withdrawn and guided towards the nearer rain draining.

Water that is accumulated in the mentioned lower enclosure is withdrawn by the referred vertical conduct, being able to use pumps of more than 800 m3/h (800 cubic meters), of the submergible or centrifugal types, indistinctly.

Although the experiments performed show that the objective is satisfactorily fulfilled, ostensibly reducing the quantity of extracting pumps on the surface, there arises the problem of costs of installation and maintenance, mainly when the construction of said collecting subsoil enclosure is commenced, which should be located in communication with the first impermeable stratum.

DESCRIPTION OF THE INVENTION

The facility to which this patent is referred to provides a mucho more feasible option than the previously described proposals, as, having a lower installation and maintenance cost, it is possible to obtain better results, covering a greater operating range with less effort.

Its operating conception is based on the fact that one same horizontal gallery boring extending adjacent to the first impermeable stratum or phreatic aquifer, acts as a complete functional unit for lowering underground sheet of waters.

Therefore, the same horizontal gallery boring is used for installing a perforated pipe collecting the liquid from the water table, y also for the resource for extracting the collected fluid in order for it to be biased to surface draining streambeds.

The task of collecting water is carried out by gravity, as each of the collecting pipes has multiple borings, which ensures that water satisfactorily flows without drawing sediment.

As it was previously indicated these borings which have their source and end on surface, in their larger length extend in communication with the first impermeable stratum or phreatic aquifer, which usually will be 10 meters to 15 meters approximately.

By means of a previous study, the optimum depth towards which the water table should be lowered is determined and it is at such depth where horizontal gallery borings shall run. It is determined based on the hydrogeological features of each area.

It is about substantially horizontal borings and with great extension as they may reach lengths of 1000 meters between the surface source and end mouths.

As it has been said, they are horizontal borings as, the main part of their length extends across the aquifer, where water which is being accumulated in the bored pipe, is withdrawn by at least one extracting piping extending inside the former and which is associated with a respective extracting pump located on the surface.

The invention provides for the option of developing embodiments wherein various extracting pipes for each bored collecting piping are used, which shall have different lengths and thus being able to simultaneously suction from different points the collected water. In these cases, each extracting piping is associated with a respective surface extracting pump.

The invention contemplates that the mentioned extracting piping may have sections with through borings and grooves, which benefits suction from the surface and avoids the formation of turbulences.

The invention also provides for resorting to the use of the so-called “submergible pumps” or “deep well pumps” having capacities of more than 800 m3/hr (800 cubic meters), in which case one single pump, associated with one single extracting pipe, causes water exit through one of the boring ends.

Deep well pumps are located within the bored pipe, such that the extracting piping, through which water is driven, runs inside it up to the surface where discharge takes place.

Also the option of combining the use of surface pumps with deep well pumps is provided for, each of them associated with a respective extracting piping. It is about a joint and coordinated work which improves the efficiency of the facility.

In order to put into practice the application purpose of the invented facility, as indicated in the title itself (multiple horizontal gallery wells), we resort to the use of a plurality of these horizontal gallery borings which are radially arranged and conveniently equally separated ones from the others for covering a great operating range and producing an homogeneous draining.

In numerous cases borings may descend up to 15 meters approximately, up to the first impermeable layer, taking into account that they may have a diameter of 400 mm or larger.

Within its internal space, the mentioned collecting pipe runs coaxially, which is distinguished because it is constituted by multibored pipes, having a sufficiently large diameter so as to enable that one or more extracting pipes run inside it.

The referred horizontal gallery borings, are built with known smart boring machines, Trenchless Technology, which are used for making “tunnels” or borings from 150 mm of diameter up to measures higher than 400 mm of diameter, below the existing facilities or buildings, that is to say, with a depth of 15 meters.

According to this invention each of these borings is internally covered by the cited uptaking bored pipes, which preferably work across all the boring length.

The invention also provides that this type of facility may be applied as a system for intercepting underground sheets of water upstream the rain runoff, for preventing the entry to the area which is intended to be protected.

In this case we resort to a series of equivalent facilities, each of which comprises its respective plurality of units for lowering the underground sheets of water extending in communication with the subsoil stream, duly separated between them forming a succession of chained facilities which define a barrier, either rectilinear or circular enclosing a population or site of interest.

As previously indicated, each facility is constituted by a plurality of horizontal borings, taking into account that some of them cross the subsoil enclosures of two consecutive wells.

Inventive Activity

No facility for lowering water tables of the ones known to present, proposes, or even suggests, the constructive solution arising from what is indicated in the previous paragraphs, this is the reason for why this is a proposal that, apart from being novel, ha a clear inventive activity.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to explain the advantages so simply set forth, to which users and those skilled in the art will be able to add many others, and to facilitate the understanding of constructive, constitutive and functional features, of the invented facility, there follows a description of a preferred example of the embodiment, which is schematically illustrated and without a determined scale, in the attached illustrations, with the clear explanation that, precisely, as it is an example, it is not appropriate to assign thereto a restricted or exclusive nature of the scope of protection of this patent of the invention but simply it is intended for explaining or illustrating the basic conception on which it is based.

FIG. 1 is a vertical view which shows a section of a unit for lowering the underground sheet of water, suitable for being part of a facility with horizontal gallery wells with surface pumps, which meets the conditions established by this invention.

FIG. 2 is a cross-section view according to the tracking plane II-II indicated in the previous figure.

FIG. 3 is an enlarged, vertical detail, which shows the combination of means which are part of each boring for the case in which surface pump are used.

FIG. 4 is a vertical view which shows a section of a unit for lowering the underground sheet of water, suitable for being part of a facility with horizontal gallery wells with deep well pumps, which meets the conditions established by this invention.

FIG. 5 is a cross-section view according to the tracking plane V-V trace indicated in the previous figure.

FIG. 6 is an enlarged, vertical detail, which shows the combination of means which are part of each boring for the case in which deep well pumps are used.

FIG. 7 is a vertical scheme of an urban area, wherein a barrier for the protection against the rise of water tables is included, with surface pumps.

FIG. 8 is a vertical scheme of an urban area, wherein a barrier for the protection against the rise of water tables is included, with deep well pump.

It is explained that in all figures, same numbers and characters of reference, correspond to same or equivalent part or elements constituting the group according to the example chosen for this explanation of the invented facility.

DETAILED DESCRIPTION OF THE PREFERRED EXAMPLES

As it can be appreciated in FIG. 1, the facility with multiple horizontal gallery wells for lowering water tables to which this patent of the invention is referred, is comprised of at least one horizontal gallery boring (1) which begin in a point (2) defined on the surface of a land (S), and progressively descends up to a depth adjacent to the aquifer, through which it extends during most of the pace traveled, for then rising to the surface.

The depth of this boring should be up to the first impermeable stratum usually called phreatic aquifer.

Precisely, the so-called horizontal gallery boring, because most of its length extends horizontally through the aquifer, that is to say, at a depth between 10 meters and 15 meters approximately, where the water table should be located. It function is, precisely, to cause it lowering.

It is about very long borings a they can be extended 1000 meters between the entry and exit points, proving that they have a great capacity of uptaking liquid.

It is about borings formed by “smart” boring machines” of the type which use boring tool and which form the tunnel, which move forward in a subsoil course by mean of a remote drive which is controlled from the outside.

Preferably, they will be borings which diameter will be able to range from 150 mm to 400 mm, explaining that it is possible to reach higher diameter.

For this purpose thee borings are distinguished because they are internally covered with a collecting pipe (3) having multiple borings, this is why they allow the passage of water collected by them, that is to say, water uptaking in all the length of the boring is sought without drawing sludge.

In fact, observing especially FIGS. 1 and 4 it is possible to see clearly the principle of operation of the invented facility, where water present on each boring falls by gravity and is collected for through at least one extracting piping (4) it is extracted and directed to surface drainage channels.

Thus, through a continuous work of several similar simultaneous borings the depression of the water table is reached from a predetermined zone to more appropriate depth levels.

In the case of FIG. 1, the extraction of collected water is accomplished by surface pumps (6), in an amount of one per each extracting piping used.

The experiments conducted indicate that these surface pumps (6) are very efficient in cases where the impermeable stratum is located approximately by 10 meters.

For these cases, as shown in FIGS. 2 and 3 two extracting piping (4) and (5) may be used, each of them having its inlet free end at spaced points, and the respective extraction pumps (6) may be installed on the surface in correspondence of the inlet and outlet ends of the same boring, so that it is a simultaneous work that increases the capacity and rate of extraction.

Looking now at the FIG. 4, the case where the horizontal gallery boring (1) extends at a greater depth (approximately 15 m) is observed.

For this case, the work is optimized using a deep well pump (8) which, as is per se known, works by impulsion displacing the liquid which is collected into one of the surface ends (9).

In these cases, the deep well pump (8) is located directly at the boring, while the extracting piping (7) runs along the inside of said casing pipe (3) having multiple affected borings,

Details of the FIGS. 5 and 6 show precisely that for this option just one pump (8) is enough to achieve a large extraction capacity for a single outlet pipe (7).

The great advantage of the invented facility is clearly seen in the schemes (A) and (B) representative of urban areas shown in FIGS. 7 and 8, where the respective facilities with horizontal gallery wells are represented orderly distributed.

It is clarified that it is simply a representation that is intended to show the wide range of action obtained with the facility invented so it is possible to achieve the depression of an underground sheet of waters homogeneously in an affected population with an inexpensive maintenance.

Thus, it will be possible to implement chained facility alignments, duly spaced from each other to form barriers (I) (FIG. 7), where surface pumps are used, or barriers (J) (FIG. 8) where deep well pumps are used.

Such facility thus distributed is also very useful to define a system for interception of underground sheet of waters upstream of a runoff to prevent it from entering the area to be protected. This is a series of horizontal wells facilities spanning the underground stream and arranged at an appropriate distance from each other.

In this sense, circular closings may be planned enclosing a population or zone that needs to be protected. In this case all the facilities are kept interconnected through horizontal gallery borings always defined in a dimension above the impermeable stratum and within the phreatic aquifer.

Thus, using the invented facility barriers may be established to enable depress a zone of over eighty hectares requiring an average length of 2,400 meters, even in fully urbanized areas. 

Having thus described and illustrated the nature and main subject matter of this invention, as well as the way in which it should be carried out in practice, it is claimed as property and exclusive right:
 1. A FACILITY WITH WELLS HAVING MULTIPLE HORIZONTAL GALLERIES FOR LOWERING WATER TABLES, suitable for being located as system for lowering water tables in a determined geographic location, comprising a set of enlarged horizontal gallery borings, which descend up to the first impermeable layer (phreatic aquifer), and extend therein at a length many times greater than the distance with respect to the ground level; each boring being internally covered with a collecting piping involved with multiple borings, in which interior at least one water extracting pipe runs which is associated with a corresponding extracting pump driving water towards outside guiding it to draining surface courses.
 2. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 1, characterized in that enlarged horizontal gallery borings have a diameter greater than 100 mm.
 3. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 1, characterized in that horizontal gallery borings extend over a depth greater than 8 meters.
 4. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 1, characterized in that borings of horizontal galleries being part of a facility are arranged spaced apart one from the other.
 5. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 1, characterized in that a surface pump is located in at least one of the ends of the horizontal gallery borings, which is associated with the extracting piping extending inside the piping involved having multiple borings.
 6. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 5, characterized in that the extracting piping extending inside the piping involved having multiple borings, includes through openings and grooves (for optimizing suction and preventing the formation of turbulences).
 7. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 1, characterized in that, a deep well pump is located inside each horizontal gallery borings, which is associated with the extracting piping extending inside the piping involved having multiple borings.
 8. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 1, characterized in that, extracting piping associated with surface extracting pumps are located inside the horizontal gallery borings, combined with extracting piping associated with deep well pumps located at a point inside the boring.
 9. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 1, characterized in that horizontal gallery borings are long-shape tunnels constructed by smart “boring machines” which comprise a drilling tool driven from an external control, which are covered with piping having multiple borings.
 10. A FACILITY WITH HORIZONTAL GALLERY WELLS, as claimed in 1, characterized in that it comprises a plurality of horizontal gallery borings constituting protecting barriers of underground sheets of water upstream the rain runoff. 